Field
Exemplary embodiments of the invention relate to an alignment apparatus, an exposure apparatus including the same, and a manufacturing method of a liquid crystal display.
Description of the Background
When performing a plurality of thin film processes on an insulation substrate or a semiconductor substrate, an alignment apparatus for aligning each thin film process may be needed.
In the alignment apparatus, a structure of an alignment key formed on the insulation substrate or the semiconductor substrate is sensed by a camera, and the next thin film process is performed based on the sensed structure.
The thin film process has a nanoscale sensitivity, however a general camera may not have nanoscale sensitivity. Accordingly, an expensive camera may need to be used or the alignment key is formed to be larger than the nanoscale to be sensed by the general camera.
Accordingly, a space occupied by the alignment key may be unnecessarily large relative to the thin film process such that an unnecessary consumption of space occurs, or the cost of the alignment apparatus is increased by the usage of the expensive camera.
With respect to a polarizer used in the thin film process, a metal line of a minute pattern may be used with an interval smaller than a wavelength of light to have a polarization characteristic. The minute pattern of the metal line is very small such that it is difficult to sense the interval therebetween by using the general camera.
When executing the thin film process on the metal line, a misalignment between the metal line of the minute pattern and the overlying thin film process may occur. This is because the metal line is pressed by using a mold to form the minute pattern when forming the metal line of the minute pattern. However, a possibility of an angle deviation is high in the pressing process.
Also, a liquid crystal display (LCD) is manufactured by combining an upper substrate and a lower substrate, and when using the general polarizer, the polarizer may be attached after the upper substrate and the lower substrate are combined such that it is not necessary to consider the alignment.
When using the metal line of the minute pattern as the polarizer, the upper substrate and the lower substrate already include the metal line of the minute pattern and the combination is executed in an aligned state. However, it is difficult to verify the alignment state of the LCD.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.